I use my oakley micro clear bag to clean my iphone. I figured if it is good enough for oakley polarized lenses, then it is probably just as good, and will not do any harm to my iphone. But come on, probably everyone has a screen protector and an overpriced rubber band on their iphones so there's really no point in being too careful with the screen. I do not use any liquid to clean the phone. I just keep on wiping it until it's clean.